CN111448043B

CN111448043B - Prepreg, laminate, method for producing the same, printed wiring board, and semiconductor package

Info

Publication number: CN111448043B
Application number: CN201880079062.2A
Authority: CN
Inventors: 清水麻理; 藤本大辅; 小竹智彦; 高根泽伸; 清水明; 青柳浩一
Original assignee: Showa Denko KK
Current assignee: Lishennoco Co ltd
Priority date: 2017-12-08
Filing date: 2018-12-10
Publication date: 2022-05-13
Anticipated expiration: 2038-12-10
Also published as: CN111448044A; CN111448043A; US20200404783A1; CN111448044B; JP7210847B2; CN111432995A; WO2019112065A1; JPWO2019112067A1; TW201932283A; KR20200092979A; TW202327858A; JPWO2019112065A1; WO2019111416A1; JPWO2019112066A1; WO2019112067A1; TWI798309B; JPWO2019111416A1; TW201925291A; TW201930423A; TWI805658B

Abstract

A prepreg which can reduce warpage is provided. Specifically disclosed is a prepreg containing a glass fiber and a thermosetting resin composition, which contains a layer in which a plurality of glass fiber filaments are arranged so as to extend substantially in parallel in one direction, wherein the content of an inorganic filler contained in the thermosetting resin composition is 1-12 vol% based on the entire prepreg. The invention also provides a method for producing the prepreg, a laminated board containing the prepreg, a method for producing the laminated board, a printed wiring board containing the laminated board, and a semiconductor package having a semiconductor element mounted on the printed wiring board.

Description

Prepreg, laminate, method for producing the same, printed wiring board, and semiconductor package

Technical Field

The present invention relates to a prepreg, a laminated board, a method for producing the same, a printed wiring board, and a semiconductor package.

Background

In recent years, demands for thinning and weight reduction of electronic devices have been increasing, and thinning and densification of semiconductor packages and printed wiring boards have been progressing. In order to stably mount electronic components while coping with these reductions in thickness and density, it is important to suppress warpage generated during mounting.

One of the main causes of warpage generated in a semiconductor package during mounting is a difference in thermal expansion coefficient between a laminate used for the semiconductor package and a silicon wafer mounted on the surface of the laminate. Therefore, efforts have been made to make the thermal expansion coefficient of the laminated plate for a semiconductor package close to that of a silicon wafer, i.e., to lower the thermal expansion coefficient.

A normal plain weave glass cloth prepreg used for a laminate is reinforced by crossing weft yarns with warp yarns in a vertically staggered state, for example (see fig. 6), and therefore, it is difficult for resin to infiltrate into the crossing portions. Thus, the content of glass fibers in the prepreg is generally stopped at less than 50% by volume. Therefore, since plain glass cloth prepregs have a limit to the reduction in thermal expansion by glass fibers in the prepregs, in order to reduce warpage, high-filling with inorganic filler materials and/or use of resins having a low thermal expansion coefficient have been gradually started (for example, see patent document 1). However, the high filling of the inorganic filler may cause a decrease in insulation reliability, a decrease in adhesion between the resin and the wiring layer formed on the surface thereof, and a press molding failure in the production of the laminate.

Under such circumstances, attempts have been made to reduce warpage by devising the structure of the prepreg. In general, a glass fiber prepreg to be provided in a laminate is manufactured by impregnating a thermosetting resin into a glass cloth woven with "glass fiber bundles" formed of a plurality of glass fiber filaments (japanese patent No. ガラス , フィラメント) as warp yarns and weft yarns, and semi-curing the glass cloth. Similarly, as a prepreg using glass fiber bundles, there is known a glass fiber prepreg (see fig. 7) including at least two layers, a layer having a glass fiber content of 60 wt% or more and 75 wt% or less and extending parallel to one direction of glass fiber bundles and a layer having a glass fiber bundle extending in another direction substantially orthogonal to the one direction, for the purpose of dimensional stability, suppression of a thermal expansion coefficient, and improvement of surface smoothness, the glass fiber prepregs each having a basis weight of 40 glass fibers of the above layersg/m²Hereinafter (see patent document 2).

The prepreg described in patent document 2 is thinned by using glass fiber filaments having a small fiber diameter and forming glass fiber bundles having a small number of bundles, and although the prepreg has a high content of glass fibers, the upper limit of the content of glass fibers in the prepreg is 75 wt% (59 vol% in terms of volume ratio), which is not sufficient in terms of reduction in thermal expansion, and further improvement is desired from the viewpoint of reduction in warpage.

On the other hand, in order to improve the impregnation of the resin composition into the glass fibers and to improve the surface smoothness when the laminate is produced, a unidirectional glass fiber prepreg has been proposed which uses, instead of a plain glass cloth used for a general prepreg, a sheet obtained by aligning a plurality of glass fiber bundles at a predetermined fiber opening index in place of the plain glass cloth (see patent document 3).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2004-182851

Patent document 2: japanese patent No. 5076340

Patent document 3: japanese laid-open patent publication No. H09-323380

Disclosure of Invention

Problems to be solved by the invention

In the examples of patent document 3, unidirectional glass fiber prepregs in which the resin component in the prepreg is increased to 40 wt% are disclosed, but further studies by the present inventors have revealed that there is still room for improvement from the viewpoint of suppressing warpage at the time of mounting.

The present invention has been made in view of such a situation, and an object thereof is to provide a prepreg capable of reducing warpage, a method for producing the prepreg, a laminate sheet containing the prepreg, a method for producing the laminate sheet, a printed wiring board containing the laminate sheet, and a semiconductor package having a semiconductor element mounted on the printed wiring board.

Means for solving the problems

The present inventors have made intensive studies to solve the above problems, and as a result, have found that the above problems can be solved if a prepreg is formed by arranging glass fiber filaments in a predetermined direction and containing a predetermined amount of an inorganic filler in a thermosetting resin composition in the prepreg, and have completed the present invention.

The present invention relates to the following [1] to [15 ].

[1] A prepreg comprising a glass fiber and a thermosetting resin composition, wherein the prepreg comprises a layer in which a plurality of glass fiber filaments are arranged to extend substantially in parallel in one direction, and the content of an inorganic filler in the thermosetting resin composition is 1 to 12 vol% based on the entire prepreg.

[2] The prepreg according to the above [1], which does not contain a glass fiber bundle in which 50 or more glass fiber filaments are bundled, or which contains the glass fiber bundle in an amount of 10 vol% or less based on the total amount of glass fibers in the prepreg.

[3] The prepreg according to the above [1] or [2], wherein the total content of the glass fiber and the inorganic filler is 50 to 75 vol% based on the entire prepreg.

[4] The prepreg according to any one of the above [1] to [3], wherein a total content of the glass fiber and the inorganic filler is 60 to 75% by volume based on the entire prepreg.

[5] The prepreg according to any one of the above [1] to [4], wherein the inorganic filler is at least 1 selected from the group consisting of silica, alumina, barium sulfate, talc, mica, kaolin, boehmite, beryllium oxide, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum borate, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, zinc borate, zinc stannate, zinc oxide, titanium oxide, silicon carbide, silicon nitride, boron nitride, clay, glass powder and hollow glass beads.

[6] The prepreg according to any one of the above [1] to [5], having a thickness of 100 μm or less.

[7] A laminated sheet comprising the prepreg according to any one of the above [1] to [6],

the laminated sheet contains: a layer in which a plurality of glass fiber filaments are arranged to extend substantially in parallel in one direction; and a layer in which a plurality of glass fiber filaments are arranged to extend substantially in parallel in another direction different from the one direction.

[8] The laminated plate according to item [7] above, wherein the other direction different from the one direction is another direction substantially orthogonal to the one direction.

[9] The laminated plate according to item [7] or [8], wherein an upper portion and a lower portion are substantially plane-symmetrical from a center in a cross section in a thickness direction of the laminated plate.

[10] The laminated plate according to any one of the above [7] to [9], wherein an average thermal expansion coefficient at 30 to 120 ℃ is 13 ppm/DEG C or less.

[11] A printed wiring board comprising the laminate according to any one of [7] to [10 ].

[12] A semiconductor package having a semiconductor element mounted on the printed wiring board as recited in the above [11 ].

[13] A method for producing a prepreg, comprising the steps of:

(1) a fiber opening step of opening the glass fiber bundle to form a plurality of glass fiber filaments;

(2) and a step of forming a prepreg containing 1 to 12 vol% of an inorganic filler by extending and disposing a plurality of glass fiber filaments formed in the fiber opening step substantially in parallel in one direction on the surface of a support material coated with a thermosetting resin composition containing an inorganic filler on the surface.

[14] A method for manufacturing a laminated board, comprising the steps of:

(2) a step of forming a prepreg containing 1 to 12 vol% of an inorganic filler by extending and disposing a plurality of glass fiber filaments formed in the fiber opening step substantially in parallel in one direction on a surface of a support material coated with a thermosetting resin composition containing an inorganic filler on the surface;

(3) preparing 2 or more prepregs formed by the step (2), laminating at least a pair of prepregs so that the extending direction of the plurality of glass fiber filaments in one prepreg is different from the extending direction of the plurality of glass fiber filaments in the other prepreg, and heating and pressing the prepregs.

[15] The method of producing a laminated plate according to item [14], wherein a direction in which the plurality of glass fiber filaments in one prepreg extend is substantially orthogonal to a direction in which the plurality of glass fiber filaments in another prepreg extend.

Effects of the invention

According to the present invention, a prepreg with reduced warpage can be provided. Further, a method for producing the prepreg, a laminate sheet containing the prepreg, a method for producing the laminate sheet, a printed wiring board containing the laminate sheet, and a semiconductor package having a semiconductor element mounted on the printed wiring board can be provided.

The prepreg and the laminate of the present invention can be made thinner, and therefore can contribute to thinning of a printed wiring board and a semiconductor package.

Drawings

Fig. 1 is a conceptual diagram showing a glass fiber bundle and a plurality of glass fiber filaments after opening.

FIG. 2 is a conceptual diagram showing one embodiment of the prepreg of the present invention.

Fig. 3 is a conceptual diagram showing an embodiment of the laminate of the present invention.

Fig. 4 is a conceptual diagram showing another embodiment of the laminate of the present invention.

Fig. 5 is a conceptual diagram showing another embodiment of the laminate of the present invention.

Fig. 6 is a conceptual diagram illustrating a plain glass cloth.

Fig. 7 is a conceptual diagram showing an embodiment of the prepreg disclosed in patent document 2.

Fig. 8 is a conceptual diagram illustrating a laminated plate manufactured in comparative example 4.

Detailed Description

In the numerical ranges described in the present specification, the upper limit or the lower limit of the numerical range may be replaced with the values shown in the examples. The lower and upper limits of a numerical range may be arbitrarily combined with the lower or upper limits, respectively, of other numerical ranges.

Unless otherwise specified, the components and materials exemplified in the present specification may be used singly or in combination of two or more kinds. All the embodiments in which the items described in the present specification are arbitrarily combined are included in the present invention.

The present invention will be described in detail below with reference to the accompanying drawings as necessary.

[ prepreg ]

The prepreg of the present invention is a prepreg including glass fibers and a thermosetting resin composition, the prepreg including a layer in which a plurality of glass fiber filaments are arranged to extend substantially in parallel in one direction, and the thermosetting resin composition includes an inorganic filler in an amount of 1 to 12 vol% based on the entire prepreg. Here, the prepreg generally means: the thermosetting resin composition is applied to a fiber substrate, dried by heating, and semi-cured.

Generally, glass fibers used for prepregs are glass fiber bundles in which a plurality of glass fiber filaments are bundled with a bundling agent and twisted as necessary, and these glass fiber bundles are also called strands (japanese: original system), and commercially available glass fibers are also glass fiber bundles (see the left side of fig. 1). As a general knowledge, the glass fiber bundles are used for the production of a prepreg in a state of being broken in order to avoid fuzz or the like due to breakage, but the prepreg of the present invention instead uses a plurality of glass fiber filaments (see the right side of fig. 1) obtained by preliminarily opening the glass fiber bundles.

According to the study of the present inventors, it was clarified that: the prepreg of the present invention has a greatly increased content of glass fibers in the prepreg and a greatly increased content of glass fibers in a laminate sheet to be described later. The exact reason for obtaining such results is not clear, but it is believed that: since the glass fiber bundles are bundled by the bundling agent, there is a loss corresponding to the volume of the bundling material, and a predetermined size is required for bundling, and there is a limit to the amount present per unit volume. And it is clear that: in the prepreg of the present invention, warpage is further effectively improved by containing 1 to 12 vol% of an inorganic filler with respect to the entire prepreg.

In the present specification, substantially parallel means: including a state of being completely parallel, and a state of being substantially parallel, if not completely parallel. In addition, the overall display may be referred to as a substantially parallel state, and even if there are fine points that are not parallel, they are included in "substantially parallel" as long as they are macroscopically parallel.

(fiber-opening method)

The above-mentioned opening method is not particularly limited, and a known opening method can be used. For example, it is possible to employ: the method of opening the fiber is at least one selected from (a) a method of stroking with a round bar (Japanese: a pellet でしごく), (b) a method of applying vibration, (c) a method of impacting with a fluid, and the like. As the opening method, not only the opening method of glass fiber but also other fibers, for example, carbon fiber can be applied. The above methods (a) to (c) may be combined arbitrarily, or may be combined in arbitrary numbers.

As a method of stroking with a round bar (a), for example, the following methods can be employed: a method of passing a fiber bundle through rollers alternately arranged vertically while applying tension to the fiber bundle and running the fiber bundle between the rollers (see, for example, japanese patent application laid-open No. 60-9961).

As a method of (b) applying the vibration, for example, the following method can be employed: a method of bringing a fiber bundle into contact with a round bar vibrated by ultrasonic waves (see, for example, japanese patent application laid-open No. h 01-282362); a method of spreading fibers by using a transverse vibration roller that vibrates in the axial direction of the roller and/or a longitudinal vibration roller that vibrates vertically with respect to the traveling direction of the fiber bundle (see, for example, japanese patent application laid-open No. 2004-225222); and the like.

As a method of (c) the impact with the fluid, for example, the following methods can be employed: a method of blowing a fluid such as water, a mixture of water and air, or an organic solvent to a fiber bundle (for example, japanese unexamined patent publication No. s 52-151362); a method of blowing an air stream to a fiber bundle (for example, japanese patent laid-open No. s 57-77342); a fiber opening method in which a fiber bundle is drawn out from each of a plurality of filament feeders and supplied, the supplied fiber bundle is caused to travel in an air flow in a plurality of fluid passage portions, and the fiber bundle is opened in the width direction while being deflected by the action of the air flow, and at this time, the fiber bundle that is moving is caused to locally expand and contract, and the tension is alternately and repeatedly changed in such a manner as tension, slack, and · · and the like (for example, refer to japanese patent application laid-open No. 2007 and 518890). Further, for example, an opening method described in japanese patent No. 5553074 may be adopted.

Further, as a combination of (b) a method of applying vibration and (c) a method of impacting with a fluid, the following methods can be cited: for a continuously traveling fiber bundle, a transverse vibration applying roller vibrating in a fiber bundle width direction and/or a longitudinal vibration applying roller vibrating in a direction intersecting with a fiber bundle traveling direction is used to perform fiber opening, and an air flow is blown to one side surface and the other side surface of a fiber bundle traveling surface to disperse the fiber bundle and perform fiber opening (for example, refer to japanese patent application laid-open No. 2005-163223).

In other words, the prepreg of the present invention can be also referred to as: the prepreg comprises glass fibers and a thermosetting resin composition, and comprises a layer in which glass fibers obtained by splitting glass fiber bundles are arranged to extend substantially in parallel in one direction, wherein the content of an inorganic filler contained in the thermosetting resin composition is 1 to 12 vol% based on the entire prepreg.

The glass fiber bundle may be split into 1 fiber and 1 fiber, or may be split into a plurality of fibers.

The number of the glass fiber bundles to be used is not particularly limited, and may be, for example, 100 to 15,000, 100 to 10,000, 500 to 10,000, 1,000 to 10,000, and 3,000 to 8,000.

The opening magnification is not particularly limited, and may be, for example, 1.2 to 5.0 times, 1.5 to 4.0 times, or 1.8 to 3.5 times. The opening ratio is an index of how much the glass fiber bundle is opened.

The temperature at the time of opening is not particularly limited, but is usually preferably 0 to 60 ℃, more preferably 5 to 45 ℃, further preferably 10 to 40 ℃, and particularly preferably performed at normal temperature.

Fig. 2 is a view showing a cross-sectional structure of a prepreg 1 as one embodiment of the present invention, and is a state of being sandwiched by a base material 2. As shown in fig. 2, at the time of producing the prepreg 1, carrier materials 2 formed of a polyethylene film, a polyethylene terephthalate film, a release paper, or a copper foil are bonded to both surfaces. When the carrier material 2 is a copper foil, the carrier material can be used as a copper foil for forming a circuit in a state of being attached to the prepreg 1.

As shown in fig. 2, the prepreg 1 contains a plurality of glass fiber filaments uniformly (japanese: ten thousand なく) in 1 layer, and preferably does not contain a glass fiber bundle in which, for example, 50 or more glass fiber filaments are bundled from the viewpoint of low thermal expansion and high elasticity, and even if such a glass fiber bundle is contained, the content thereof is preferably 10 vol% or less, more preferably 5 vol% or less, and still more preferably 2 vol% or less with respect to the total amount of glass fibers in the prepreg. In particular, from the viewpoint of low thermal expansion and high elasticity, it is preferable that 100 or more bundled glass fiber bundles are not contained, preferably 200 or more bundled glass fiber bundles are not contained, preferably 500 or more bundled glass fiber bundles are not contained, and even if these glass fiber bundles are contained, the content thereof is preferably 10 vol% or less, more preferably 5 vol% or less, and still more preferably 2 vol% or less, respectively, with respect to the total amount of glass fibers in the prepreg.

From the viewpoint of filling property, the fiber diameter (diameter) of the glass fiber filament is preferably 3 to 50 μm, more preferably 3 to 40 μm, still more preferably 4 to 30 μm, particularly preferably 5 to 25 μm, and most preferably 5 to 18 μm.

In the prepreg of the present invention, the total content of the glass fiber and the inorganic filler may be 50 to 75 vol%, 55 to 75 vol%, 60 to 75 vol%, or 65 to 75 vol% based on the entire prepreg. Therefore, the prepreg has a high glass fiber existence rate, and thus can achieve low thermal expansion, and thus tends to be effective in reducing warpage. When the content of the glass fiber is 75 vol% or less based on the entire prepreg, the ratio of the thermosetting resin composition 4 is not excessively decreased, and the occurrence of whitening on the surfaces of the prepreg and the laminate due to insufficient impregnation of the

glass fiber filaments

31 and 32 can be suppressed.

The total content (volume ratio) of the glass fiber and the inorganic filler in the prepreg can be determined by, for example, the following method, without limitation. The mass ratio A of the inorganic components (i.e., glass fibers and inorganic filler) is determined by dividing the mass of the solid component (residue) obtained by heating the prepreg at 600 to 650 ℃ by the mass of the prepreg before heating, and the mass ratio B of the resin component in the prepreg is determined from the mass ratio A. The volume ratio of the inorganic component can be calculated by calculating the volume of the inorganic component and the volume of the resin component from the mass ratio a and the density of the inorganic component, and the mass ratio B and the density of the resin component.

Further, since the glass fiber filaments obtained by the opening are used, the thickness of the prepreg can be adjusted to be thin. The thickness of the prepreg of the present invention may be 100 μm or less, 70 μm or less, or 50 μm or less. The thickness of the prepreg is preferably 30 to 80 μm, more preferably 35 to 70 μm, and still more preferably 35 to 65 μm. A plurality of the prepregs may be stacked and used.

(thermosetting resin composition)

As described above, the prepreg of the present invention is a prepreg containing glass fibers and a thermosetting resin composition. In the present invention, the thermosetting resin composition further effectively improves warpage by containing the inorganic filler in an amount of 1 to 12 vol% based on the entire prepreg. For example, when the content of the glass fiber in the prepreg is 70 vol%, if an amount corresponding to 5 vol% of the content of the glass fiber is replaced with the inorganic filler, the effect of suppressing warpage is improved although the total amount of inorganic substances in the prepreg is the same. The exact reason for this effect is not clear, but it is known that: in the prepreg including the layer in which the plurality of glass fiber filaments are arranged to extend substantially in parallel in one direction, this effect can be obtained when the content of the inorganic filler in the thermosetting resin composition is the predetermined amount.

The thermosetting resin composition is not particularly limited as long as it contains the inorganic filler in the above-mentioned predetermined amount, and a known thermosetting resin composition used for a prepreg in the field of printed wiring boards can be used.

The respective components that the thermosetting resin composition may contain are not particularly limited, and examples thereof include (a) a thermosetting resin, (B) a curing accelerator, (C) an inorganic filler, and (D) other additives. In the present invention, (C) the inorganic filler is an essential component, as described above.

Examples of the thermosetting resin (a) include: epoxy resins, phenol resins, unsaturated imide resins, cyanate ester resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, melamine resins, and the like. In addition, the resin composition is not particularly limited to these, and a known thermosetting resin can be used. These may be used alone or in combination of two or more.

Examples of the epoxy resin include: bisphenol a-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, α -naphthol/cresol novolac-type epoxy resins, bisphenol a novolac-type epoxy resins, bisphenol F novolac-type epoxy resins, stilbene-type epoxy resins, triazine skeleton-containing epoxy resins, fluorene skeleton-containing epoxy resins, triphenol methane-type epoxy resins, biphenyl-type epoxy resins, xylylene-type epoxy resins, biphenyl aralkyl-type epoxy resins, naphthalene-type epoxy resins, dicyclopentadiene-type epoxy resins, alicyclic epoxy resins, polyglycidyl ether compounds of polycyclic aromatic species such as polyfunctional phenols and anthracenes, phosphorus-containing epoxy resins obtained by introducing a phosphorus compound into these epoxy resins, and the like.

Examples of the unsaturated imide resin include a maleimide compound having at least 2N-substituted maleimide groups in 1 molecule, and the maleimide compound may be a reaction product with at least one selected from a monoamine compound and a diamine compound.

As the curing accelerator (B), a known curing accelerator can be used depending on the kind of the thermosetting resin (a). Examples of the curing accelerator for epoxy resins include: a phosphorus-based compound; imidazole compounds and derivatives thereof; a tertiary amine compound; quaternary ammonium compounds, and the like. These may be used alone or in combination of two or more.

The inorganic filler (C) is not particularly limited, and examples thereof include silica, alumina, barium sulfate, talc, mica, kaolin, boehmite, beryllium oxide, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum borate, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, zinc borate, zinc stannate, zinc oxide, titanium oxide, silicon carbide, silicon nitride, boron nitride, clay (fired clay, etc.), glass powder, and hollow glass beads, and preferably at least 1 selected from these. Among these, silica is preferable as the (C) inorganic filler. The silica is not particularly limited, and examples thereof include crushed silica, fumed silica, fused silica (fused spherical silica), and the like, and fused silica (fused spherical silica) is preferable.

(C) The specific surface area of the inorganic filler is preferably 3m²More than g, and may be 3 to 200m²A/g, which may be 3 to 130m²A/g, which may be 3 to 50m²A/g, which may be 3 to 20m²(ii) in terms of/g. The specific surface area can be determined by the BET method based on low-temperature low-humidity physical adsorption of an inert gas. Specifically, molecules having a known adsorption occupation area of nitrogen or the like are adsorbed on the surface of the powder particles at a liquid nitrogen temperature, and the specific surface area of the powder particles can be determined from the adsorption amount.

The volume average particle diameter of the (C) inorganic filler is preferably 0.01 to 5 μm, more preferably 0.1 to 2 μm, and still more preferably 0.2 to 1 μm, from the viewpoint of obtaining good embeddability of the circuit board and insulation reliability. The volume average particle diameter means: when a cumulative frequency distribution curve based on the particle diameter is obtained assuming that the total volume of the particles is 100%, the particle diameter of a point corresponding to 50% of the volume can be measured by a particle size distribution measuring apparatus using a laser diffraction scattering method or the like.

As the inorganic filler (C), an inorganic filler surface-treated with a surface-treating agent such as a silane coupling agent can be used from the viewpoint of adhesion to the resin component.

The content of the (C) inorganic filler in the thermosetting resin composition is 1 to 12 vol% based on the entire prepreg, and from the viewpoint of reducing warpage, the content is preferably 2 to 12 vol% based on the entire prepreg, more preferably 3 to 11 vol%, and may be 3 to 8 vol% based on the entire prepreg, or may be 8 to 11 vol%.

The other additive (D) is not particularly limited, and may be at least one selected from organic fillers, flame retardants, thermoplastic resins, thermoplastic elastomers, ultraviolet absorbers, antioxidants, photopolymerization initiators, fluorescent brighteners, adhesion improvers, and the like.

The thermosetting resin composition may further contain an organic solvent, a dispersant, and the like. Among these, since the organic solvent is volatilized in a drying step in the production of the prepreg, the organic solvent tends not to substantially remain in the prepreg.

[ laminated sheet ]

Generally, a plurality of the prepregs are laminated and heated and pressed to form a laminate. In particular, the laminated plate of the present invention is a laminated plate including the prepreg, and the laminated plate includes a layer in which a plurality of glass fiber filaments are arranged to extend substantially parallel in one direction and a layer in which a plurality of glass fiber filaments are arranged to extend substantially parallel in another direction different from the one direction.

In the present invention, it is preferable that the other direction different from the one direction is another direction substantially orthogonal to the one direction. Specifically, the laminated sheet 5 shown in fig. 3, which represents one embodiment of the present invention, is preferably formed of one layer in which a plurality of longitudinal glass fibers 31 are arranged to extend substantially parallel to each other in the front-rear direction of the sheet, and the other layer in which transverse glass fibers 32 are arranged to extend substantially parallel to each other in the direction substantially orthogonal to the longitudinal glass fibers 31. The thermosetting resin composition 4 is present around these glass fiber filaments. Here, the substantially orthogonal means that: including states that are fully orthogonal, and states that are substantially, if not fully orthogonal. In addition, the overall display may be referred to as a substantially orthogonal state, and even if there are subtle places that are not orthogonal, they are included in "substantially orthogonal" as long as they are macroscopically orthogonal.

The layer containing the glass fiber filaments 31 and the layer containing the glass fiber filaments 32 are different in the direction of the glass fiber filaments, and the fiber diameter, the length, the glass fiber content, and the like of each glass fiber filament are almost the same, and the volume ratio of the glass fibers is almost equal, whereby the dimensional changes in the longitudinal direction and the transverse direction of the laminated plate 5 are also almost equal.

The laminate of the present invention is preferably: in a cross section of the laminated plate in the thickness direction, an upper portion and a lower portion are substantially plane-symmetrical from the center. By adopting this way, the warpage can be effectively reduced. Here, "substantially plane-symmetrical" means that the upper part and the lower part are plane-symmetrical from the center, not focusing on the positions of 1 and 1 glass fiber filaments, but focusing on the arrangement direction of the glass fiber filaments. For example, the laminated plate shown in fig. 4 is preferable in that the upper portion and the lower portion are plane-symmetrical from the center portion shown in the figure, and the warpage is reduced. The laminated plate shown in fig. 5 is also preferable from the viewpoint of reducing warpage because the upper portion and the lower portion are plane-symmetrical from the center.

In the laminate sheet of the present invention, the total content of the glass fibers and the inorganic filler may be 50 to 75 vol%, 55 to 75 vol%, 60 to 75 vol%, or 65 to 75 vol% with respect to the entire laminate sheet (in the case of a laminate sheet having a metal foil, the metal foil is not included).

The laminate of the present invention is not particularly limited, but the average thermal expansion coefficient at 30 to 120 ℃ can be 13 ppm/DEG C or less. More preferably 12 ppm/DEG C or less, still more preferably 11 ppm/DEG C or less, and particularly preferably 10 ppm/DEG C or less. The lower limit of the average thermal expansion coefficient is not particularly limited, and tends to be 7 ppm/DEG C or more, and may be 8 ppm/DEG C or more. The average thermal expansion coefficient is a value measured by the method described in examples.

[ method for producing prepreg ]

The present invention also provides a method for producing a prepreg comprising the following steps.

(1) And a fiber opening step of opening the glass fiber bundle to form a plurality of glass fiber filaments.

(2) And a step of forming a prepreg containing 1 to 12 vol% of an inorganic filler by extending the plurality of glass fiber filaments formed in the fiber opening step substantially in parallel in one direction on the surface of the support material coated with the thermosetting resin composition containing an inorganic filler on the surface [ hereinafter, sometimes referred to as step (2) ]. ].

The glass fiber bundle is opened by the opening step to form a plurality of glass fiber filaments. The method of opening is not particularly limited as described above, and for example, the above-described opening method can be employed.

In the step (2), the method of arranging the plurality of glass fiber filaments to extend substantially in parallel in one direction on the surface of the support material having the thermosetting resin composition containing the inorganic filler applied to the surface thereof is not particularly limited, and the plurality of glass fiber filaments obtained through the fiber opening step may be directly aligned and arranged on the surface of the support material, or the plurality of glass fiber filaments obtained through the fiber opening step may be once taken up by a roll, cut as necessary, and then aligned and arranged on the surface of the support material.

The thermosetting resin composition containing an inorganic filler is as described above.

[ method for producing laminated plate ]

The present invention also provides a method for producing a laminated plate having the following steps.

(2) And a step (2) of forming a prepreg containing 1 to 12 vol% of an inorganic filler on the surface coated with a carrier material of a thermosetting resin composition containing an inorganic filler, by extending and disposing the plurality of glass fiber filaments formed in the fiber opening step substantially in parallel in one direction.

(3) A step of preparing 2 or more prepregs formed by the step (2), laminating at least a pair of prepregs so that the extending direction of the plurality of glass fiber filaments in one prepreg is different from the extending direction of the plurality of glass fiber filaments in the other prepreg, and heating and pressing the laminated prepregs [ hereinafter, sometimes referred to as a step (3) ]. ].

The opening step and the step (2) are as described in the method for producing a prepreg.

In the step (3), it is preferable that the extending direction of the plurality of glass fiber filaments in one prepreg is substantially orthogonal to the extending direction of the plurality of glass fiber filaments in the other prepreg. For example, this embodiment can be implemented by stacking 2 prepregs formed by the above step (2) while changing the orientation.

In the step (3), the heating and pressing conditions may be those for producing a usual laminate, and for example, the laminate may be produced by using a multistage press, a multistage vacuum press, continuous molding, autoclave molding machine or the like at a temperature of 100 to 260 ℃, a pressure of 0.2 to 10MPa, and a heating time of 0.1 to 5 hours.

[ printed Wiring Board ]

The invention also provides a printed wiring board containing the laminated board. More specifically, a plurality of prepregs of the present invention are prepared, and a metal-clad laminate is produced by laminating and molding a metal foil of copper, aluminum or the like on one or both surfaces thereof, and a wiring pattern is formed on the metal foil, whereby a printed wiring board can be produced. The metal foil is not particularly limited as long as it is used for an electrical insulating material, and a copper foil is preferable. The method of forming the wiring pattern is not particularly limited, and known methods such as a subtractive method, a full-Additive method, a Semi-Additive method (SAP) and a modified Semi-Additive method (m-SAP) can be used.

[ semiconductor Package ]

The present invention also provides a semiconductor package having a semiconductor element mounted on the printed wiring board. The semiconductor package may be manufactured as follows: a semiconductor element such as a semiconductor chip or a memory is mounted on a predetermined position of the printed wiring board, and the semiconductor element is sealed with a sealing resin or the like.

Examples

The present invention will be described in further detail with reference to the following examples, which are not intended to limit the scope of the present invention. A copper-clad laminate in which a copper foil was disposed on the laminate produced in each example was produced, and the obtained copper-clad laminate was immersed in a copper etching solution to remove the copper foil, thereby producing an evaluation substrate and using the evaluation substrate for the following evaluation. The evaluation method is shown below.

(1) Determination of the average coefficient of thermal expansion

A test piece 5mm square was cut out from the above evaluation substrate. The average thermal expansion coefficient was determined by a compression method using a thermomechanical analyzer TMA (Q400, manufactured by TA Instruments Co., Ltd.) at a measurement temperature ranging from-20 to 320 ℃ under an applied weight of 0.1N, and the average thermal expansion coefficient was determined in a range of from 30 to 120 ℃.

(2) Determination of warpage

A40X 40mm square test piece was cut out from the above evaluation substrate. A20X 20mm semiconductor silicon substrate was bonded to the substrate to prepare a substrate for warpage measurement.

Warpage of the substrate was measured using a SHADOW moir apparatus (THERMOIRE PS-200, manufactured by AKROMETRIX Co.). With respect to the measurement conditions, the amount of warpage when the temperature was increased from 25 ℃ to 260 ℃ and then cooled to 25 ℃ was measured, and the value obtained when the warpage obtained in comparative example 2 was taken as the reference (100) was calculated.

(3) Evaluation of whitening

The laminated sheets produced in the respective examples were visually observed and evaluated according to the following evaluation criteria.

A: no graying was observed at all.

B: only a small amount of whitish was observed.

C: more whitish was observed.

Production example 1 (production of thermosetting resin composition 1; resin composition for containing 5 vol% of inorganic filler in prepreg)

"NC-7000L" (trade name, manufactured by Nippon chemical Co., Ltd.) as an epoxy resin, "addition reaction product of bismaleimide compound and a diamine compound as a maleimide resin," G-8009L "(trade name, imidazole-blocked isocyanate (Japanese: イソシアネートマスクイミダゾール), manufactured by first Industrial pharmaceutical Co., Ltd.) as a curing accelerator, fused spherical silica (trade name, average particle diameter 0.5 μm, manufactured by Admatechs, Ltd.) as an inorganic filler, "YoshiNOx BB" as an antioxidant (trade name, 4' -butylidenebis- (6-tert-butyl-3-methylphenol), manufactured by Mitsubishi chemical corporation) was mixed with a mixed solvent of methyl ethyl ketone and cyclohexanone to obtain a thermosetting resin composition 1 having a solid content of 55 mass%.

Production example 2 (production of thermosetting resin composition 2; resin composition for containing 10 vol% of inorganic filler in prepreg)

"NC-7000L" (trade name, manufactured by Nippon Kabushiki Kaisha) as an epoxy resin, "addition reaction product of bismaleimide compound and diamine compound as a maleimide resin," G-8009L "(trade name, imidazole-blocked isocyanate, manufactured by first Industrial pharmaceutical Co., Ltd.) as a curing accelerator," fused spherical silica "(trade name, average particle diameter 0.5 μm, manufactured by Admatechs Co., Ltd.) as an inorganic filler," YosHINOX BB "[ trade name, 4' -butylidenebis- (6-tert-butyl-3-methylphenol), manufactured by Mitsubishi chemical corporation ] as an antioxidant was mixed in a mixed solvent of methyl ethyl ketone and cyclohexanone to obtain a thermosetting resin composition 2 having a solid content concentration of 55 mass%.

Production example 3 (production of thermosetting resin composition 3; containing no inorganic filler)

"NC-7000L" (trade name, manufactured by Nippon chemical Co., Ltd.) as an epoxy resin, "addition reaction product of bismaleimide compound and diamine compound as a maleimide resin," G-8009L "(trade name, imidazole-blocked isocyanate, manufactured by first Industrial pharmaceutical Co., Ltd.) as a curing accelerator," YosHINOX BB "[ trade name, 4' -butylidenebis- (6-tert-butyl-3-methylphenol), manufactured by Mitsubishi chemical Co., Ltd.) as an antioxidant was mixed in a mixed solvent of methyl ethyl ketone and cyclohexanone to obtain a thermosetting resin composition 3 having a solid content concentration of 55 mass%.

Production example 4 (production of thermosetting resin composition 4; resin composition for containing 30 vol% of inorganic filler in prepreg (comparative)

"NC-7000L" (trade name, manufactured by Nippon Kabushiki Kaisha) as an epoxy resin, "addition reaction product of bismaleimide compound and diamine compound as a maleimide resin," G-8009L "(trade name, imidazole-blocked isocyanate, manufactured by first Industrial pharmaceutical Co., Ltd.) as a curing accelerator," fused spherical silica "(trade name, average particle diameter 0.5 μm, manufactured by Admatechs Co., Ltd.) as an inorganic filler," YoshiNOX BB "[ trade name, 4' -butylidenebis- (6-tert-butyl-3-methylphenol), manufactured by Mitsubishi chemical corporation ] as an antioxidant was mixed in a mixed solvent of methyl ethyl ketone and cyclohexanone to obtain a thermosetting resin composition 4 having a solid content concentration of 55 mass%.

Production example 5 (production of thermosetting resin composition 5; resin composition for containing 25 vol% of inorganic filler in prepreg (comparative)

"NC-7000L" (trade name, manufactured by Nippon Kabushiki Kaisha) as an epoxy resin, "addition reaction product of bismaleimide compound and diamine compound as a maleimide resin," G-8009L "(trade name, imidazole-blocked isocyanate, manufactured by first Industrial pharmaceutical Co., Ltd.) as a curing accelerator," fused spherical silica "(trade name, average particle diameter 0.5 μm, manufactured by Admatechs Co., Ltd.) as an inorganic filler," YosHINOX BB "[ trade name, 4' -butylidenebis- (6-tert-butyl-3-methylphenol), manufactured by Mitsubishi chemical corporation ] as an antioxidant was mixed in a mixed solvent of methyl ethyl ketone and cyclohexanone to obtain a thermosetting resin composition 5 having a solid content concentration of 55 mass%.

Production example 6 (production of thermosetting resin composition 6; containing no inorganic Filler (for comparison))

"NC-7000L" (trade name, manufactured by Nippon chemical Co., Ltd.) as an epoxy resin, "addition reaction product of bismaleimide compound and diamine compound as a maleimide resin," G-8009L "(trade name, imidazole-blocked isocyanate, manufactured by first Industrial pharmaceutical Co., Ltd.) as a curing accelerator," YosHINOX BB "[ trade name, 4' -butylidenebis- (6-tert-butyl-3-methylphenol), manufactured by Mitsubishi chemical Co., Ltd.) as an antioxidant was mixed in a mixed solvent of methyl ethyl ketone and cyclohexanone to obtain a thermosetting resin composition 6 having a solid content concentration of 55 mass%.

Example 1

The thermosetting resin composition 1 obtained in production example 1 was coated on a carrier material having a thickness of 10 μm using a polyethylene terephthalate film having a thickness of 38 μm as the carrier material, to form a resin coating film 1 having a thickness of 10 μm.

Next, a glass fiber bundle obtained by bundling 6,000 glass fiber filaments having a fiber diameter (diameter) of 12 μm was opened at an opening magnification of 2.6 times, and the opened glass fiber filaments were aligned in the transverse direction to a width of 300mm and aligned on the resin coating film 1 having a thickness of 10 μm. On this, another sheet of the above-described resin-coated film 1 having a thickness of 10 μm was attached with the resin-coated surface facing downward.

The prepreg precursor thus obtained was subjected to B-staging using a hot roll at a pressure of 1MPa, a temperature of 150 ℃ and a conveying speed of 1 m/min, thereby obtaining a prepreg having a glass fiber content of 60 vol% (the total content of glass fibers and inorganic filler is 65 vol%).

The prepregs prepared as described above were stacked on 8 sheets as shown in FIG. 5, and heated and pressed by a vacuum press under conditions of a temperature rise rate of 3 ℃/min, a holding time of 85 minutes at 245 ℃ and a pressure of 2MPa to obtain a stacked plate.

Using the obtained laminated sheet, each evaluation was performed according to the above-described method. The results are shown in Table 1.

Example 2

In example 1, a prepreg having a glass fiber content of 60 vol% (the total content of the glass fiber and the inorganic filler is 70 vol%) was obtained by performing the same operation as in example 1 except that the thermosetting resin composition 2 obtained in production example 2 was coated on the above-mentioned support material to form a resin coating film 2 having a thickness of 10 μm and the resin coating film 2 was used in place of the resin coating film 1. Using this prepreg, a laminate was produced in the same manner as in example 1.

Each evaluation was performed by the above method using the obtained laminated sheet. The results are shown in Table 1.

Reference example 1

In example 2, a prepreg having a glass fiber content of 58 vol% was obtained by performing the same operation as in example 2 except that the thermosetting resin composition 3 (containing no inorganic filler) obtained in production example 3 was coated on the above-mentioned carrier material in a thickness of 10 μm instead of the thermosetting resin composition 2 to form a resin coating film 3 having a thickness of 10 μm and the resin coating film 3 was used in place of the resin coating film 2. Using this prepreg, a laminated plate was produced in the same manner as in example 1.

Comparative example 1

In example 2, a prepreg having a glass fiber content of 40 vol% (the total content of glass fibers and inorganic filler is 70 vol%) was obtained in the same manner as in example 2 except that the thermosetting resin composition 4 obtained in production example 4 was coated on the above-mentioned support material in a thickness of 15 μm to form a resin coating film 4 having a thickness of 15 μm, the resin coating film 4 was used in place of the resin coating film 2, and the glass fiber bundle was spread in a spreading ratio of 3.5 times. Using this prepreg, a laminate was produced in the same manner as in example 2.

The total content of the glass fibers and the inorganic filler in the laminated sheet was 70 vol%, which was the same as the total content of the glass fibers and the inorganic filler in the laminated sheet produced in example 2.

Comparative example 2

In example 2, plain glass cloth (100 g/m) was used as the glass fiber²) Thermosetting resin composition 5 obtained in production example 5 was dip-coated on plain glass cloth in place of thermosetting resin composition 2, and then heated and dried at 110 ℃ for 3 minutes to obtain a glass fiber content of 45 volA laminated board was produced in the same manner as above except that% (the total content of the glass fiber and the inorganic filler was 70 vol%).

Although the total content of the glass fibers and the inorganic filler in the laminated sheet was 70 vol%, which was the same as the total content of the glass fibers and the inorganic filler in the laminated sheet produced in example 2, the laminate suffered from warpage (in table 1, the warpage amount of the laminate of comparative example 2 was taken as a reference (100)), and reduction of the warpage was the subject of the present invention.

Comparative example 3

A prepreg having a glass fiber content of 60 vol% (the total content of the glass fiber and the inorganic filler being 85 vol%) was obtained by the same procedure as in comparative example 2 except that the content and the coating amount of the inorganic filler in the thermosetting resin composition 5 were adjusted in comparative example 2, and a laminated plate was produced in the same manner as in comparative example 2.

An attempt was made to reduce warpage by increasing the total content of the glass fibers and the inorganic filler in the laminate relative to comparative example 2(70 vol%), thereby reducing thermal expansion, and as a result, a large amount of whitening was observed on the surface of the laminate.

Comparative example 4

According to the method described in patent document 2, a glass fiber bundle, which is formed by bundling 200 glass fiber filaments having a fiber diameter (diameter) of 5 μm, is aligned directly on a resin coating film 6 coated with a thermosetting resin composition 6 and having a thickness of 10.5 μm at a pitch of 0.5mm without opening the fiber. The resin coating film 6 having the thickness of 10.5 μm was attached to the surface of the prepreg so that the resin coating surface faced downward, and a prepreg containing glass fiber bundles in a content critical to the extent that blooming started to occur was obtained.

The B-staging was carried out using a hot roll at a pressure of 1MPa, a temperature of 150 ℃ and a conveying speed of 1 m/min, resulting in the formation of a prepreg having a glass fiber content of 59% by volume.

The prepregs prepared as described above were laminated on 8 sheets as shown in FIG. 8, and heated and pressed by a vacuum press under conditions of a temperature rise rate of 3 ℃ per minute, a holding time of 85 minutes at 245 ℃ and a pressure of 2MPa to obtain a laminated sheet. A large amount of whitening was observed on the surface of the resulting laminate. The prepreg produced by the method described in patent document 2 has a glass fiber content of 59% by volume, and a large amount of white blur is generated, and it can be said that there is a limit to the reduction of the thermal expansion coefficient and there is room for improvement in the effect of reducing warpage.

[ Table 1]

TABLE 1

As is clear from table 1, in the examples, the content of the glass fiber in the prepreg and the laminate was increased, and also, no blush was observed in the laminate and the warpage was reduced.

On the other hand, in reference example 1, although the thermal expansion coefficient was about the same as that of example, the warpage was not reduced. In comparative example 1, although the thermal expansion coefficient was about the same as that of example, the surface of the laminated plate was slightly whitened, and the warpage was not reduced. In comparative example 2, the thermal expansion coefficient was about the same as that in example 2, and the total content of the glass fiber and the inorganic filler was the same as that in example 2, but warpage occurred. In comparative example 3 in which the glass fiber content was increased in order to improve the warpage of comparative example 2, a large amount of whiting was generated on the surface of the laminate sheet as described above. In comparative example 4, as described above, much whitening was observed on the surface of the laminated sheet.

Industrial applicability

The prepreg and the laminate of the present invention have sufficiently reduced warpage and are therefore useful as a printed wiring board for electronic devices.

Description of the symbols

1 prepreg

2 support Material

3 glass fiber filaments

4 Heat-curable resin composition

5 laminated plate

31 longitudinal glass fibre filaments

32 transverse glass fibre filaments

Claims

1. A prepreg comprising a glass fiber and a thermosetting resin composition, wherein the prepreg comprises a layer in which a plurality of glass fiber filaments are arranged to extend substantially in parallel in one direction, the thermosetting resin composition contains an inorganic filler in an amount of 1 to 12 vol% based on the entire prepreg, and the total content of the glass fiber and the inorganic filler is 50 to 75 vol% based on the entire prepreg.

2. The prepreg according to claim 1, wherein the glass fiber bundles obtained by bundling 50 or more glass fiber filaments are not contained, or the content of the glass fiber bundles is 10 vol% or less based on the total amount of glass fibers in the prepreg.

3. The prepreg according to claim 1 or 2, wherein the total content of the glass fiber and the inorganic filler is 60 to 75 vol% based on the entire prepreg.

4. The prepreg according to claim 1 or 2, wherein the inorganic filler material is at least 1 selected from the group consisting of silica, alumina, barium sulfate, talc, mica, kaolin, boehmite, beryllia, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum borate, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, zinc borate, zinc stannate, zinc oxide, titanium oxide, silicon carbide, silicon nitride, boron nitride, clay, glass powder, and hollow glass beads.

5. A prepreg according to claim 1 or 2, which has a thickness of 100 μm or less.

6. A laminate comprising the prepreg according to any one of claims 1 to 5,

7. The laminated plate of claim 6, wherein the other direction different from the one direction is another direction substantially orthogonal to the one direction.

8. The laminated plate according to claim 6 or 7, wherein an upper portion and a lower portion are substantially plane-symmetrical from a center in a cross section in a thickness direction of the laminated plate.

9. The laminate of claim 6 or 7, wherein the average coefficient of thermal expansion is 13ppm/° C or less at 30-120 ℃.

10. A printed wiring board comprising the laminate as claimed in any one of claims 6 to 9.

11. A semiconductor package having the semiconductor element mounted on the printed wiring board according to claim 10.

12. A method for producing a prepreg, comprising the steps of:

(2) a step of forming a prepreg containing 1 to 12 vol% of an inorganic filler by extending and disposing a plurality of glass fiber filaments formed in the fiber opening step substantially in parallel in one direction on a surface of a support material coated with a thermosetting resin composition containing an inorganic filler on the surface,

the total content of the glass fiber and the inorganic filler is 50 to 75 vol% based on the entire prepreg.

13. A method for manufacturing a laminated board, comprising the steps of:

(3) preparing 2 or more prepregs formed by the step (2), laminating at least a pair of prepregs so that the extending direction of the plurality of glass fiber filaments in one prepreg is different from the extending direction of the plurality of glass fiber filaments in the other prepreg, and heating and pressing the prepregs,

14. A method of manufacturing a laminated panel as claimed in claim 13 wherein the direction of extension of the plurality of glass fibre filaments in one prepreg sheet is substantially orthogonal to the direction of extension of the plurality of glass fibre filaments in another prepreg sheet.